Democrats have bought $1 million worth of ad time in the upcoming special congressional election in Oregon – a significant sign that the heavily Democratic seat of former congressman David Wu (D-Ore.) could be at risk.

But just how at risk?

Neither side is insisting this race will be close. But the big early buy suggests Democrats are scared — and not necessarily because of anything that’s happening in Oregon.

Democrats say the Democratic Congressional Campaign Committee’s large early investment in the race — which concludes Jan. 31 — is geared toward ending the race early and hopefully avoiding the embarrassment of losing another heavily Democratic seat. The party lost a longtime-Democratic New York City seat in September, and even the risk of repeating that appears to be just scary enough to go whole hog in Oregon.

The logic essentially goes like this: We can spend a million dollars now and make this a no-doubter, or spend more later trying to defend a seat that, if lost, could send shockwaves through the Democratic caucus and cast doubt on the party’s ability to win back the House in 2012.

Republicans, for their part, agree that the race will be very tough for them to win, given that the disrict went more then 60 percent for President Obama in 2008. Essentially, they are taking the same approach that they took in the special election for New York’s 9th district, when they waited to see if the race was competitive, and then when it was, swooped in at the end and won.

This is a low-risk, low-cost strategy for the GOP. As in New York, they are supposed to lose, so any amount of success is nothing but a bonus. Democrats, meanwhile, have the burden of holding a seat that feasibly could be competitive but would likely never change hands in a regularly scheduled election.

But while the GOP likes to compare this race to New York’s 9th district, Democrats prefer to compare it to the other special election held in September — Nevada’s 2nd district.

In that race, the National Republican Congressional Committee spent $600,000 defending a seat the GOP candidate eventually won by more than 20 points. Was it an expensive and perhaps unnecessary investment? Yes. But it made sure that a district that could have been troublesome – Obama very nearly won it in 2008 – was effectively off the map.

Wu’s seat is similar in many respects, in that there’s really no excuse to lose it for Democrats, but anything can happen in a special election and it’s not out of the question. Of course, if the party wasn’t at least legitimately worried about losing, it wouldn’t spend $1 million trying to keep it.

“This district has a large number of non-affiliated voters that usually break Democratic, but you can’t take them for granted,” said West Coast Democratic consultant Jim Ross.

Democrats felt that they had a good candidate in state Sen. Suzanne Bonamici, but the GOP candidate, Rob Cornilles, has been running as the outsider, and that’s worth something in anti-Washington environment. The new DCCC ad hits Cornilles for associating himself with the tea party.

Cornilles campaign manager Mary Ann Ostrom said the DCCC’s ad buy shows just how scared it is.

“If that isn’t some sign of desperation, I don’t know what is,” Ostrom said.

The House campaign committees hate special elections. They are often more competitive than regular elections and usually more expensive, because they are the focus of the political world. (For comparison’s sake, $1 million is generally how much a committee will spend on one of the dozen or so most competitive races in the general election.)

And that’s not to mention the fact that the stakes are actually very low: just one of 435 House seats.

But this is a special election, so the normal rules don’t apply and money will be spent in ways it never would in a regular race in such a district.

Luckily for Democrats, even if they lose in Oregon, the loss will almost surely be overshadowed by the Florida presidential primary, which is being held the same day. (Actually, that’s really just when the race is over; because Oregon is vote-by-mail, ballots will be cast in the two weeks preceding Jan. 31.)

But the prospect of losing another special election is still something Democrats would rather avoid. If the pricetag is a million dollars to avoid that possibility, that may be a good investment in the scheme of things.

If the race starts closing, though, this could become a wholly unhelpful narrative for a DCCC that insists it’s ready to play offense.